System and method for detecting mutual capacitance

ABSTRACT

The disclosed computer-implemented method for determining a proximity status between electrodes may include detecting an amount of electrical charge an electrode among other electrodes that are communicatively coupled to an artificial reality device. The method may further include determining, based on the detected amount of electrical charge at the electrode, a mutual capacitance measurement that indicates an amount of mutual capacitance between the other electrodes. The method may also include determining, based on the mutual capacitance measurement, a relative proximity status between the electrodes, where the relative proximity status indicates a degree to which the electrodes are in proximity with each other. The method may further include providing the determined relative proximity status between the electrodes as an input to the artificial reality device. Various other methods, systems, and computer-readable media are also disclosed.

BACKGROUND

Artificial reality devices are becoming increasingly common. Many ofthese artificial reality devices employ some type of haptic feedback.This haptic feedback provides sensory inputs to users, causing the usersto feel certain sensations when, for example, touching artificialobjects in a virtual world. These haptic feedback systems are oftenincorporated into gloves, but may also be implemented in headwear,footwear, bodysuits or other wearable systems. Some types of hapticgloves may include conductive pads on the fingertips to detect touchbetween various areas of the body (e.g., between fingertips). When twosuch conductive pads touch, they form a galvanic connection causingcurrent to flow, which is detected by electronic components. Thesegalvanic connections, however, tend to get dirty and oily, resulting inunreliable connections. Moreover, conductive pads may short to eachother causing further ambiguity in detection.

Other artificial reality systems use different means to determine whenbody parts such as fingers are touching. For example, some artificialreality systems may use infrared cameras pointed at the user's hands todetermine when the user's fingers or tendons are moving. Then, fromthese movements, the artificial reality system may attempt to determinethe moment at which the user's fingers are touching. In other systems,traditional cameras may be set up to look at the user's hand's posewhich may show whether fingers are touching. In other cases, attemptshave been made to attach detectors on the backs of the user's fingersand use magnetic fields to determine where those points are in space.Then, from this 3D positioning in space, the systems will attempt todetermine when the user's fingers are touching. Still others haveattempted to use cameras to look at color changes that occur in theuser's fingernails when pressure is applied from touch. Such systemsdetermine that a user's fingers have touched when the user's fingernailshave sufficiently changed in color. None of these systems isparticularly good at pinpointing when a user's fingers have touched. Asa result, the immersive nature of the artificial reality experience maybe greatly reduced for the user.

SUMMARY

As will be described in greater detail below, the instant disclosuredescribes methods and systems that effectively determine a proximitystatus between electrodes, indicating whether a user's fingers aretouching.

In one example, a system may include at least two electrodescommunicatively coupled to an artificial reality device. The system mayalso include a controller configured to detect an amount of electricalcharge at at least one of the two electrodes and, based on the detectedamount of electrical charge, determine a mutual capacitance measurementthat indicates an amount of mutual capacitance between the twoelectrodes. The controller may also be configured to determine, based onthe mutual capacitance measurement, a relative proximity status betweenthe at least two electrodes, where the relative proximity statusindicates a degree to which the electrodes are in proximity with eachother. The controller may further be configured to provide thedetermined relative proximity status between the at least two electrodesas an input to the artificial reality device.

In some examples, the controller may determine the mutual capacitancemeasurement based on the detected amount of electrical charge at both ofthe at least two electrodes. In some examples, the controller maydetermine when insulators between the at least two electrodes aretouching each other. In some examples, the controller may determine whenthe at least two touching insulators between the electrodes have ceasedtouching each other. In some examples, the system may include three ormore electrodes communicatively coupled to the artificial realitydevice. In some examples, the controller may determine which twoelectrodes among the three or more electrodes are within a specifieddistance of each other.

In some examples, the at least two electrodes may be embedded within atleast a partial glove configured to fit on at least a portion of auser's hand. In some examples, at least one of the electrodes mayinclude a transducer configured to provide a tangible movement uponreceiving a triggering input. In some examples, the transducer may beconfigured to provide the tangible movement while the controllerdetermines the mutual capacitance measurement between the at least twoelectrodes. In some examples, signals controlling the transducer may betransferred over the same wire as signals used to detect mutualcapacitance at the transducer. In some examples, the transducer may be avibrotactor.

In some examples, the controller may receive feedback from at least oneof the electrodes, and the controller may use the received feedback tocalibrate other sensors communicatively coupled to the system.

In addition, a corresponding method for determining a proximity statusbetween electrodes may include detecting an amount of electrical chargeat at least one electrode among at least two electrodes that arecommunicatively coupled to an artificial reality device. The method mayfurther include determining, based on the detected amount of electricalcharge at the at least one electrode, a mutual capacitance measurementthat indicates an amount of mutual capacitance between the at least twoelectrodes. The method may next include determining, based on thedetermined mutual capacitance measurement, a relative proximity statusbetween the at least two electrodes, where the relative proximity statusmay indicate a degree to which the electrodes are in proximity with eachother. The method may also include providing the determined relativeproximity status between the at least two electrodes as an input to theartificial reality device.

In some examples, at least one of the electrodes may include a stretchsensor. The stretch sensor may be configured to detect an amount ofstretch in the artificial reality device while the mutual capacitancemeasurement between the at least two electrodes is being determined. Insome examples, the at least two electrodes may be embedded in anembroidered patch that is fastened to the artificial reality device. Insome examples, the artificial reality device may include at least apartial glove. In such cases, a thumb covering of the glove may includeat least two electrodes and an index finger covering of the glove mayinclude at least two electrodes.

In some examples, the method may further include detecting a slidingmovement between the at least two electrodes of the thumb covering andthe at least two electrodes of the index finger covering. In someexamples, at least one of the electrodes may be mounted into a cuff thatis positioned over at least one finger.

In some examples, multiple additional electrodes may be implemented toallow users to input gestures to the artificial reality device. In someexamples, multiple electrodes may be arranged in a pattern adjacent toeach other forming a grid of electrodes. As such, when an opposingelectrode comes into proximity with the grid of electrodes, a gridposition may be determined indicating the location of the opposingelectrode relative to the grid of electrodes.

In some examples, the above-described method may be encoded ascomputer-readable instructions on a computer-readable medium. Forexample, a computer-readable medium may include one or morecomputer-executable instructions that, when executed by at least oneprocessor of a computing device, may cause the computing device todetect an amount of electrical charge at at least one electrode among atleast two electrodes that are communicatively coupled to an artificialreality device, determine, based on the detected amount of electricalcharge at the at least one electrode, a mutual capacitance measurementthat indicates an amount of mutual capacitance between the at least twoelectrodes, determine, based on the determined mutual capacitancemeasurement, a relative proximity status between the at least twoelectrodes, where the relative proximity status indicates a degree towhich the electrodes are in proximity with each other, and provide thedetermined relative proximity status between the at least two electrodesas an input to the artificial reality device.

Features from any of the embodiments described herein may be used incombination with one another in accordance with the general principlesdescribed herein. These and other embodiments, features, and advantageswill be more fully understood upon reading the following detaileddescription in conjunction with the accompanying drawings and claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings illustrate a number of exemplary embodimentsand are a part of the specification. Together with the followingdescription, these drawings demonstrate and explain various principlesof the instant disclosure.

FIG. 1 illustrates an embodiment of an artificial reality headset.

FIG. 2 illustrates an embodiment of an augmented reality headset andcorresponding neckband.

FIG. 3 illustrates an embodiment of a virtual reality headset.

FIG. 4 illustrates an embodiment of a proximity detection system thatincludes at least two electrodes.

FIG. 5 illustrates a flow diagram of an exemplary method for determininga proximity status between electrodes.

FIGS. 6A-6C illustrate progressive embodiments in which electrodes aremoved together and are subsequently moved apart.

FIG. 7A illustrates an embodiment of a proximity detection system.

FIG. 7B illustrates an example circuit diagram for a circuit that may beincluded in the proximity detection system.

FIG. 8 illustrates an alternative embodiment of a proximity detectionsystem embedded in at least a partial glove.

FIG. 9 illustrates an alternative embodiment of a proximity detectionsystem embedded in at least a partial glove.

FIG. 10 illustrates an alternative embodiment of a proximity detectionsystem embedded in at least a partial glove.

FIG. 11 illustrates an alternative embodiment of a proximity detectionsystem embedded in at least a partial glove.

FIG. 12A illustrates an alternative embodiment of a proximity detectionsystem embedded in at least a partial glove.

FIG. 12B illustrates an alternative embodiment of a proximity detectionsystem embedded in at least a partial glove.

FIGS. 13A-13D illustrate a plurality of embodiments in which electrodemay be embroidered into artificial reality bodywear.

FIGS. 14A and 14B illustrate an alternative embodiment of a proximitydetection system embedded in at least a partial glove.

Throughout the drawings, identical reference characters and descriptionsindicate similar, but not necessarily identical, elements. While theexemplary embodiments described herein are susceptible to variousmodifications and alternative forms, specific embodiments have beenshown by way of example in the drawings and will be described in detailherein. However, the exemplary embodiments described herein are notintended to be limited to the particular forms disclosed. Rather, theinstant disclosure covers all modifications, equivalents, andalternatives falling within the scope of the appended claims.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

The present disclosure is generally directed to determining a proximitystatus between electrodes. As will be explained in greater detail below,embodiments of the instant disclosure may allow a controller or othercomputing system to determine when electrodes are close to each other,when they are touching, and when they have separated. Preciselydetermining when electrodes touch may have a large impact on anartificial reality system's ability to provide an immersive experience.For example, if a user is using an artificial reality device (e.g., anaugmented reality headset or a virtual reality headset and/or gloveswith haptic feedback), it may be frustrating to that user if theartificial reality device does not properly detect when the user'sfingers are touching.

For instance, in some cases, a haptic glove configured to provide hapticfeedback to a user may include electrodes dispersed throughout theglove. In some cases, for example, the haptic glove may include anelectrode that is placed over the user's thumb and an electrode that isplaced on the user's pointer fingertip. When the user pinches thepointer finger and thumb together, the two electrodes will come closerand closer until they touch. Through tactile sensations (apart from thehaptic glove), the user will know when their pointer finger and thumbare touching. If the haptic glove does not register a touch when theuser knows the finger and thumb are, in fact, touching, the user's brainwill register the discrepancy. This may cause the user to be removedfrom an otherwise immersive experience. Similarly, if the user's fingersare subsequently moved apart from one another and the haptic systemsdoes not register the movement, the user may get frustrated, noting thatyet another movement did not register properly. Over time, the lack ofaccuracy regarding finger touches may lead the user to stop using thehaptic glove and/or the artificial reality system altogether.

Accordingly, the embodiments herein may provide a more accurate andprecise method of determining when electrodes are touching. Otherembodiments may determine when electrodes are close to touching, but nottouching. Still other embodiments may determine when electrodes thatwere previously touching have come apart. Each of these moments (neartouching, touching, and separation) may be registered separately by thehaptic system. Each separate moment may then be used to control aspectswithin the artificial reality device including interacting with userinterfaces, interacting with virtual objects, interacting with otherusers, interacting with other devices, and so on. Still further, atleast some of the embodiments herein may implement haptic feedbackactuators to both provide haptic feedback and detect proximity of theelectrodes. As such, haptic gloves or other haptic bodywear thatimplements the embodiments herein may have fewer components and lessweight, making the gloves more desirable to wear on a long-term basis.These embodiments will be explained further below with regard to theartificial reality systems 100, 200 and 300 of FIGS. 1-3, and withfurther regard to FIGS. 4-14B.

Artificial reality systems may be implemented in a variety of differentform factors and configurations. Some artificial reality systems may bedesigned to work without near-eye displays (NEDs), an example of whichis AR system 100 in FIG. 1. AR systems that work without NEDs may take avariety of forms, such as head bands, hats, hair bands, belts, watches,wrist bands, ankle bands, rings, neckbands, necklaces, chest bands,eyewear frames, and/or any other suitable type or form of apparatus.Other artificial reality systems may be designed to work with an NEDthat may provide visibility into the real world (e.g., AR system 200 inFIG. 2) or that visually immerses a user in an artificial reality (e.g.,VR system 300 in FIG. 3). While some artificial reality devices may beself-contained systems, other artificial reality devices may communicateand/or coordinate with external devices to provide an artificial realityexperience to a user. Examples of such external devices include handheldcontrollers, mobile devices, desktop computers, devices worn by a user,devices worn by one or more other users, and/or any other suitableexternal system.

Turning to FIG. 1, AR system 100 generally represents a wearable devicedimensioned to fit about a body part (e.g., a head) of a user. As shownin FIG. 1, system 100 may include a frame 102 and a camera assembly 104that is coupled to frame 102 and configured to gather information abouta local environment by observing the local environment. AR system 100may also include one or more audio devices, such as output audiotransducers 108(A) and 108(B) and input audio transducers 110. Outputaudio transducers 108(A) and 108(B) may provide audio feedback and/orcontent to a user, and input audio transducers 110 may capture audio ina user's environment.

The embodiments discussed in this disclosure may also be implemented inAR systems that include one or more NEDs. For example, as shown in FIG.2, AR system 200 may include an eyewear device 202 with a frame 210configured to hold a left display device 215(A) and a right displaydevice 215(B) in front of a user's eyes. Display devices 215(A) and215(B) may act together or independently to present an image or seriesof images to a user.

In some embodiments, AR system 200 may include one or more sensors, suchas sensor 240. Sensor 240 may generate measurement signals in responseto motion of AR system 200 and may be located on substantially anyportion of frame 210. Sensor 240 may include a position sensor, aninertial measurement unit (IMU), a depth camera assembly, or anycombination thereof. Examples of sensor 240 may include, withoutlimitation, accelerometers, gyroscopes, magnetometers, other suitabletypes of sensors that detect motion, sensors used for error correctionof the IMU, or some combination thereof. AR system 200 may also includea microphone array with a plurality of acoustic sensors 220(A)-220(J),referred to collectively as acoustic sensors 220.

AR system 200 may further include or be connected to an external device.(e.g., a paired device), such as neckband 205. As shown, neckband 205may be coupled to eyewear device 202 via one or more connectors 230. Theconnectors 230 may be wired or wireless connectors and may includeelectrical and/or non-electrical (e.g., structural) components. In somecases, the eyewear device 202 and the neckband 205 may operateindependently without any wired or wireless connection between them.While FIG. 2 illustrates the components of eyewear device 202 andneckband 205 in example locations on eyewear device 202 and neckband205, the components may be located elsewhere and/or distributeddifferently on eyewear device 202 and/or neckband 205. In someembodiments, the components of the eyewear device 202 and neckband 205may be located on one or more additional peripheral devices paired witheyewear device 202, neckband 205, or some combination thereof.Furthermore, neckband 205 generally represents any type or form ofpaired device. Thus, the following discussion of neckband 205 may alsoapply to various other paired devices, such as smart watches, smartphones, wrist bands, gloves, other wearable devices, hand-heldcontrollers, tablet computers, laptop computers, etc.

Pairing external devices, such as neckband 205, with AR eyewear devicesmay enable the eyewear devices to achieve the form factor of a pair ofglasses while still providing sufficient battery and computation powerfor expanded capabilities. Some or all of the battery power,computational resources, and/or additional features of AR system 200 maybe provided by a paired device or shared between a paired device and aneyewear device, thus reducing the weight, heat profile, and form factorof the eyewear device overall while still retaining desiredfunctionality. Neckband 205 may also include a controller 225 and apower source 235. Moreover, the neckband may include one or moretransducers configured to provide haptic feedback to the user. Thehaptic feedback may include pulses, vibrations, buzzing or othersensations that communicate information to a user.

As noted, some artificial reality systems may, instead of blending anartificial reality with actual reality, substantially replace one ormore of a user's sensory perceptions of the real world with a virtualexperience. One example of this type of system is a head-worn displaysystem, such as VR system 300 in FIG. 3, that mostly or completelycovers a user's field of view. VR system 300 may include a front rigidbody 302 and a band 304 shaped to fit around a user's head. VR system300 may also include output audio transducers 306(A) and 306(B).Furthermore, while not shown in FIG. 3, front rigid body 302 may includeone or more electronic elements, including one or more electronicdisplays, one or more inertial measurement units (IMUS), one or moretracking emitters or detectors, and/or any other suitable device orsystem for creating an artificial reality experience.

While not shown in FIGS. 1-3, artificial reality systems may includetactile (i.e., haptic) feedback systems, which may be incorporated intoheadwear, gloves, body suits, handheld controllers, environmentaldevices (e.g., chairs, floormats, etc.), and/or any other type of deviceor system. Haptic feedback systems may provide various types ofcutaneous feedback, including vibration, force, traction, texture,and/or temperature. Haptic feedback systems may also provide varioustypes of kinesthetic feedback, such as motion and compliance. Hapticfeedback may be implemented using motors, piezoelectric actuators,fluidic systems, and/or a variety of other types of feedback mechanisms.Haptic feedback systems may be implemented independent of otherartificial reality devices, within other artificial reality devices,and/or in conjunction with other artificial reality devices.

By providing haptic sensations, audible content, and/or visual content,artificial reality systems may create an entire virtual experience orenhance a user's real-world experience in a variety of contexts andenvironments. For instance, artificial reality systems may assist orextend a user's perception, memory, or cognition within a particularenvironment. Some systems may enhance a user's interactions with otherpeople in the real world or may enable more immersive interactions withother people in a virtual world. Artificial reality systems may also beused for educational purposes (e.g., for teaching or training inschools, hospitals, government organizations, military organizations,business enterprises, etc.), entertainment purposes (e.g., for playingvideo games, listening to music, watching video content, etc.), and/orfor accessibility purposes (e.g., as hearing aids, visuals aids, etc.).The embodiments disclosed herein may enable or enhance a user'sartificial reality experience in one or more of these contexts andenvironments and/or in other contexts and environments.

FIG. 4 illustrates an example artificial reality system 400. Theartificial reality system 400 may include a controller 401, two (ormore) electrodes 413 and 414, and an artificial reality device 410. Theartificial reality device 410 may include any or all of the devices 100,200, or 300 described above with regard to FIG. 1, 2, or 3, includingaugmented reality headsets, virtual reality headsets or other artificialreality devices. The artificial reality device 410 may becommunicatively connected to the controller 401 and/or the electrodes413/414. It will be understood that, in many of the embodiments herein,the electrodes may be shown and described as being embedded in or partof a glove. The electrodes 413/414 may, however, be part of orincorporated into substantially any type of haptic feedback devicedesigned for use anywhere on a user's body. Moreover, when examplescontaining one or two electrodes are referred to herein, it will beunderstood that substantially any number of electrodes may be used inany given implementation.

The electrodes 413/414 may be made of copper, zinc, silver, gold,platinum or other conductive metals or other conductive materials suchas silicon. At least in some cases, the electrodes 413/414 may includeinsulators. For instance, the electrodes 413/414 may be embedded in aglove, where electrode 413 is embedded on the glove fingertip of theuser's pointer finger 411, and the electrode 414 is embedded on the padof the thumb 412. When the insulators on each electrode contact eachother, the electrodes may be said to be touching. In some embodiments,the electrode insulators may be made of enamel, silicone, plastic, orother insulating substance.

Each electrode may be linked to the controller 401 via a wire 415. Thecontroller 401 may be any type of electronic hardware configured toreceive and process electrical inputs, including a Field-ProgrammableGate Arrays (FPGA), an Application-Specific Integrated Circuit (ASIC),an Electrically-Erasable Programmable Read-Only Memory (EEPROM), asystem-on-a-chip, or some other type of computing hardware. Thecontroller 401 may receive electrical inputs from the electrodes 413/414via the conductive wire 415. The controller 401 may also include amemory 402 which may be configured to store software code or otherinstructions indicating how the controller is to process the electricalinputs. At least in some embodiments, the controller 401 may includemodules that perform one or more of the computational steps. Thesemodules may perform their functions solely in hardware, solely insoftware, using a combination of both hardware and software.

For example, the charge detector 403 may be configured to detect anelectrical charge received from one or more of the electrodes 413/414.For instance, the electrodes may be placed a given distance apart by auser. As the electrodes 413/414 get closer, each electrode may begin toaccumulate an electrical charge. Indeed, the two electrodes, along withan area of air that exists between the electrodes, may form a capacitorwhere air acts as the dielectric. When powered by a power supply (e.g.,in neckband 205 of FIG. 2), the electrodes 413/414 may build up anelectrical charge that is measurable by the charge detector 403. Thecharge detector 403 may detect the built-up charge at any of theelectrodes individually or may determine the amount of charge at a groupof electrodes collectively.

Once the charge detector 403 has detected at least some amount ofelectrical charge, the detected amount of charge 404 may be provided asan input to the mutual capacitance determining module 405. The mutualcapacitance determining module 405 may analyze the detected charge 404at one electrode (e.g., 413) or at both electrodes (e.g., 413/414) andmay calculate a mutual capacitance measurement 406. The mutualcapacitance measurement 406 may indicate the amount of capacitance(e.g., in analog-to-digital (ADC) counts or in some other form ofmeasurement) that exists between the two electrodes 413/414. This amountof mutual capacitance may change as the distance between the electrodes413/414 decreases or increases. For instance, the amount of mutualcapacitance between the electrodes 413/414 may increase as the amount ofdielectric material (air in this example) decreases.

This mutual capacitance measurement 406 may then be provided as an inputto the proximity status determining module 407. The proximity statusdetermining module 407 may use the mutual capacitance measurement 406 tocalculate a relative proximity status 408 between the electrodes413/414. This relative proximity status 408 may indicate how close orfar apart the electrodes are from each other (e.g., as measured inmillimeters). As the electrodes 413/414 come closer toward each other,for example, the amount of air between them acting as a dielectric willcontinue to decrease until there is no air between them and theelectrodes are touching. The controller 401 may then determine that theelectrodes 413/414 are touching and may indicate such to the artificialreality device 410. This information may be provided to the AR device410 to provide precisely-timed haptic feedback, thereby fully immersingthe user in the artificial reality experience. This process will bedescribed in greater detail below with regard to method 500 of FIG. 5and with regard to the embodiments depicted in FIGS. 6A-14B.

FIG. 5 illustrates a flow diagram of an exemplary computer- orcontroller-implemented method 500 for determining a proximity statusbetween electrodes. The steps shown in FIG. 5 may be performed by anysuitable computer-executable code and/or computing system, including thesystem illustrated in FIG. 4. In one example, each of the steps shown inFIG. 5 may represent an algorithm whose structure includes and/or isrepresented by multiple sub-steps, examples of which will be provided ingreater detail below.

As illustrated in FIG. 5, at step 510 one or more of the systemsdescribed herein may detect an amount of electrical charge at at leastone electrode among at least two electrodes that are communicativelycoupled to an artificial reality device. For example, the chargedetector 403 of controller 401 may detect an amount of electrical chargeat electrode 413 and/or electrode 414. Each of these electrodes may beconnected to the controller via a single wire (e.g., 415) or viaseparate wires.

Method 500 may next include determining, based on the detected amount ofelectrical charge 404 at the at least one electrode, a mutualcapacitance measurement 406 that indicates an amount of mutualcapacitance between the at least two electrodes (step 520). Forinstance, the mutual capacitance determining module 405 may determine amutual capacitance measurement 406 based on the detected amount ofcharge 404 in the electrodes 413/414. As opposed to traditional systemsthat measure galvanic connections between electrodes, which process isprone to malfunctions caused by oil and dirt, the mutual capacitancedetermining module 405 may be configured to determine a measure ofcapacitance between the electrodes. The mutual capacitance measurement406 may provide more than a touch or no-touch signal. Indeed, the mutualcapacitance measurement 406 may detect electrodes that are close but nottouching (e.g., within 2 mm). Moreover, the mutual capacitancedetermining module 405 may be configured to measure the distance betweenthe electrodes before they touch. In some embodiments, for example, thecharge detector 403, mutual capacitance determining module 405, and/orthe proximity status determining module 407 may be determined tofunction on a continuous or continual, repeating basis. Thus, the amountof charge detected at the electrodes may be updated each second, eachmillisecond, each microsecond, or at some other period to continuallyupdate the measurement of the distance between the electrodes 413/414.

In some embodiments, the mutual capacitance determining module 405 maybe configured to measure capacitance between two electrodes (e.g.,413/414). In such cases, neither electrode may be electrically grounded.Alternatively, the mutual capacitance determining module 405 may beconfigured to measure the capacitance between a single electrode (e.g.,413) and ground. This latter measurement may be distinguished from amutual capacitance measurement in that it may recognize when twoelectrodes have touched but may not know which electrodes have touched.On the contrary, the mutual capacitance measurement 406 may determinewhen two electrodes have touched and may determine which two electrodestouched. At least in some embodiments, mutual capacitance may also bemore tolerant to parasitic capacitances lost to ground and may thus moreeasily allow conductors (e.g., wire 415) to be routed through the systemwithout substantial loss of signal. In still further embodiments, themutual capacitance determining module 405 may be configured to measuremutual capacitance between two electrodes (e.g., 413/414) when oneelectrode is grounded, as described in related U.S. Pat. No. 9,109,939.

In cases where each fingertip includes an electrode, for example, theuser may touch their thumb to any of the electrodes in the other fingersof the user's hand. In other cases, the user may touch their thumb orother fingers to fingers on the user's other hand, or even potentiallyon another user's hand. In such cases, mutual capacitance measurementsusing signals from each individual electrode may be used to identifywhich electrodes were touched. Mutual capacitance measurements may alsoallow the controller 401 to determine whether the electrodes are closeor touching even when the each of the electrodes are moving (e.g.,relative to the user). Indeed, in the embodiments herein, none of theelectrodes needs to be fixed or immobile. Any of the electrodes may bemobile relative to each other or relative to the user and, at least insome cases, may move while mutual capacitance is being detected.

Method 500 of FIG. 5 may next include determining, based on the mutualcapacitance measurement 406, a relative proximity status 408 between theat least two electrodes (e.g., 413/414) at step 530. The relativeproximity status 408 may indicate a degree to which the electrodes413/414 are in proximity with each other. The controller 401 may thenprovide the determined relative proximity status 408 between the atleast two electrodes 413/414 as an input to the artificial realitydevice 410 at step 540. The relative proximity status 408 may indicatethe distance between two electrodes at any given point in time.

For example, as shown in FIGS. 6A-6C, two electrodes 603 and 604 may bemoved to many different positions relative to each other. In eachposition, the controller 401 of FIG. 4 may register a different detectedcharge 404 and may thus calculate a different mutual capacitance 406 anda different resulting proximity status 408. The proximity status 408 maytherefore change as the electrodes 603 and 604 of FIG. 6 are movedtoward each other and away from each other. In FIG. 6A, for example, theelectrodes 603/604 may be positioned within a short enough distance thata mutual capacitance may be measured relative to the two electrodes(this distance may vary depending on the size of the electrodes, thechemical composition of the electrodes, or other environmental factorssuch as those that would affect the dielectric).

In FIG. 6B, the electrodes 603/604 may be moved to within touchingdistance. In FIG. 6C, the finger 601 and thumb 602 may be moved farenough apart that the controller no longer registers a mutualcapacitance (i.e., the electrical charges 404 at the electrodes aresmall enough that the mutual capacitance between the electrodes 603/604is negligible). Accordingly, the controller may detect not only when theelectrodes 603/604 are touching, but also when the electrodes havestopped touching. Moreover, after the electrodes are sufficiently closeto create a capacitive effect between them, the controller may determinethe relative distance between the two electrodes 603/604. This may betrue even if both of the electrodes are moving relative to the user(e.g., the user is waving their hand).

Accordingly, the controller 401 may be configured to determine a mutualcapacitance measurement 406 based on an amount of electrical chargedetected at at least one electrode (e.g., 603) and may also determine amutual capacitance measurement 406 based on an amount of electricalcharge detected at two different electrodes (e.g., 603/604). Using thismutual capacitance measurement 406, the controller 401 may determinewhen the two electrodes are touching each other. In cases where a hapticglove, body suit, or other piece of haptic equipment includes multipledifferent electrodes, the controller 401 may not only determine that twoelectrodes are touching but may also determine which two electrodes aretouching.

For example, as shown in FIG. 7A, the left-side box 700A illustrates thepalm side of a user's hand with a glove 710. The glove may include aplurality of embedded electrodes 701-705. The electrodes 701-705 may beembedded, for example, in the fingertips of each finger on the glove. Asin the embodiments shown in FIG. 6A-6C, the user may touch their thumb,for example, to any of their fingers. Thus, when electrode 701 on thethumb touches electrode 702 on the pointer finger or touches electrode703 on the middle finger or touches electrode 704 on the ring finger ortouches electrode 705 on the pinky finger, the controller 708 may beable to determine when the respective electrodes are close, touching orseparated. The back side of the user's hand, shown in the right-side box700B, may include one or more conducting wires 707 that connect eachelectrode to the controller 708. Still further, the back-side of theuser's hand may include other electrodes, for example, positionedbetween the user's thumb and pointer finger (e.g., electrode 706 (whichmay be a reference electrode, as explained further below)). Many otherelectrodes may be embedded on the haptic glove 710 in addition toelectrodes 701-706.

In some embodiments, the haptic glove 710 may be constructed from apower mesh. The electrodes 701-706 may be integrated into this powermesh. The power mesh may be a type of fabric mesh made of nylon,spandex, or other material that is designed to stretch. Haptic glovesconstructed of such material may be more comfortable to a variety ofusers as the gloves may stretch to accommodate substantially any shapeor size of hand. In FIG. 7A, electrodes are located at each fingertipand at the thumb tip. Each electrode may be connected to the controller708 (e.g., a printed circuit board (PCB)) using one or more conductors707.

In some cases, the conductors 707 may include enameled wire. In someembodiments, this wire may be 30-guage or smaller in diameter, and inother embodiments, the wire may be 34-guage or smaller. Smaller wire maybe more flexible and thus more comfortable for the user to wear. In someembodiments, the conductors 707 may comprise silicone-jacketed, 30-guage(or smaller) stranded wire. The conductors 707 may be insulated to avoidunintended electrical connection. Alternatively, the conductors 707 maybe non-insulated such as, for example, conductive thread. The electrodes701-706 may be insulated using various materials to shield theelectrodes from the user's body and from other conductors to avoidmeasurement errors. In some embodiments, the conductors 707 may beattached to the haptic glove 710 in a serpentine pattern so that theconductors are free to move and conform to the user's hand.Alternatively, flexible conductors may be implemented in the hapticglove 710. Such flexible conductors may be attached to the haptic glove710, for example, by stitching across the conductors using thread.

When operating (e.g., when connected to an artificial reality headset orother artificial reality system (e.g., any of 100, 200 or 300 from FIG.1, 2, or 3, respectively)), the controller 708 may drive a signal on oneelectrode and detect the effect on a second electrode. The firstelectrode may be referred to as a transmit electrode (TX), and thesecond electrode may be referred to as a receive electrode (RX). The TXelectrode may be driven at a relatively low impedance and the RXelectrode may form a high impedance input to a sensing circuit (e.g.,controller 708). As a result, in at least some embodiments, anyparasitic capacitance between TX electrodes may be neglected. On theflipside, any parasitic capacitance between TX and RX electrodes may bereduced by maintaining a minimum spacing of at least 5 mm, for example,between TX conductors and RX conductors. In some embodiments, electrodes701 and 706 may be RX electrodes and electrodes 702, 703, 704, and 705may be TX electrodes. By placing the controller 708 on the back of thehand and by routing the conductors 707 over the backs of the fingers, anoptimal spacing for TX and RX electrodes may be provided.

Additionally or alternatively, each RX conductor may be shielded using ashielding material to reduce coupling to TX conductors. Alternatively,each TX conductor may be shielded, or both RX and TX conductors may beshielded. The shielding may, for example, encircle each of theconductors 707. In other cases, shield wires may be routed adjacent tothe shielded conductor (e.g., within 1 mm). The shield may be connectedto system ground or may be driven to match the shielded conductor. Thecontroller 708 may thus drive a single TX electrode and may then measurethe received signal on one or more RX electrodes. In this manner,measurements across TX and RX electrodes may be time multiplexed withinthe system. To assist in the measurement process, electrode 706 may beimplemented as a reference electrode. In some cases, portions of asignal may couple from a TX electrode, through the user's body, to an RXelectrode. The reference electrode (e.g., 706) may be used to correctfor this coupling that occurs through the user's body. The referenceelectrode may be place in a location on the glove (or other hapticdevice) where it is unlikely that another electrode will touch it. Insome embodiments, the reference electrode 706 may be a TX electrode andin other cases, the reference electrode 706 may be an RX electrode.

In some embodiments, it may be advantageous to limit the number of RXelectrodes because the RX electrodes are designed to supply a highimpedance and, as a result, their conductors may be more difficult toroute as they are more susceptible to parasitic coupling to TXconductors. In such cases, the glove 710 may include fewer RX electrodesthan TX electrodes. Conductors (e.g., 707) may also be routed to avoidsharp bend areas such as the palm side of the base of the fingers. Suchrouting may limit sharp bends on the conductors, potentially avoidingpremature failures. Routing the conductors in this manner may alsoimprove user comfort while wearing the glove 710. The electrodes 701-706and/or the controller 708 may be mounted to an embroidered patch on theglove 710, as will be explained further below.

Thus, a haptic glove such as 710 may include many different electrodesarranged in a variety of different locations. The controller 708 mayreceive inputs from RX electrodes indicating charge levels at thoseelectrodes. From this charge, the controller 708 may determine a mutualcapacitance measurement between any two of the electrodes that are closeenough to begin generating a measurable mutual capacitance. Thecontroller may determine which two electrodes are within a specifieddistance of each other and may determine what that distance is.Moreover, the controller 708 may determine when the electrodes aretouching, how long they are touching, and when the two electrodesseparate from each other, all using the mutual capacitance measurement.Each of these moments may be used in a user interface to controlinteractions with that user interface and/or interactions with virtualobjects.

In some embodiments, one or more of the electrodes 701-706 may be atransducer that is configured to provide a tangible movement uponreceiving a triggering input. These transducers may be the elements in ahaptic glove that provide the haptic feedback. The transducers mayreceive an input signal from the controller 708 or from anothercontroller (e.g., a controller within an artificial reality headset suchas 300 of FIG. 3) and may produce a movement such as a buzz or avibration that may be felt by the user. In some embodiments, thesetransducers may be implemented as electrodes 701-706 in the haptic glove710.

One example of such transducers or actuators is a vibrotactor. Avibrotactor may be a flexible piezo material that vibrates uponreceiving an input drive signal. For instance, the controller 708 mayapply a sine wave input signal (e.g., at 200V) and the vibrotactor mayflex in proportion to the amount of voltage applied across the piezoelement. Vibrotactors may be small and may conforms well to the user'sfingers. Each vibrotactor may have a conductor which may be used ascapacitive plate. The embodiments herein may temporarily disconnect theexisting piezo drive system and apply a higher frequency signal toperform the capacitive coupling. Indeed, at least in some embodiments,the higher-frequency signal applied to the vibrotactor may cause thebuildup of electrical charge at the conductor that is used as acapacitive plate.

The controller 708 may, for example, send a TX signal to the vibrotactorwhich causes the vibrotactor to vibrate. In some embodiments, thatsignal may be at a frequency of around 100 Hz. In between such TXsignals, or before or after such signals, the controller 708 may send ahigher-frequency signal to the vibrotactor to detect the electricalcharge buildup (e.g., electrical charge 404 of FIG. 4). This higherfrequency signal (e.g., in the KHz or MHz range) may not be reproducedby the vibrotactor or, if the vibrotactor is capable of reproducing thesignal, the signal may not be felt by the user. As such, detectingelectrical charge 404 (and therefore mutual capacitance) may beperformed at a higher frequency, while haptic feedback actuations may beperformed at a lower frequency. Thus, the same transducer (e.g., avibrotactor) may be used as both an electrode and an actuator.

For example, FIG. 7B illustrates one embodiment of a circuit diagram 750that may be implemented in or accessed by the controller 708 of FIG. 7A.In some embodiments, the circuit diagram 750 may provide drive signalsfor vibrotactors (VTs). For instance, VT drive 1 (VT1 751) may drive afirst vibrotactor and VT drive 2 (VT2 752) may drive a secondvibrotactor. In some cases, VT1 may be the transmitter and VT2 may bethe receiver. Both VTs may be driven by high voltage VT drives (751/752)through series resistors R1 and R2 (e.g., at 1 k ohms each). Duringmeasurements, the positive terminal of VT2 may be disconnected from theVT drive 752 by opening a high-voltage switch 753. The negative terminalmay be disconnected from ground by opening switch 7. In such cases, VT2would now be a high-impedance receiver (RX).

The negative terminal of VT1 may be connected to a high-current logicdriver that outputs specified voltages (e.g., 0V or 5V). The driver mayhave sufficiently low impedance to overcome the current through R2. Thedriver may be controlled by a pulse generator 754. The pulses may be,for example, 1.7 uS wide with 10 pulses in a sequence. Sequence durationmay be, for example, 34.5 uS and may repeat every 10 mS, for example(i.e., 0.4% duty cycle). At least in some cases, the vibrotactorresponse time may be too slow to react to pulses of this speed and, assuch, the pulses may be implemented in a manner that will not degradethe vibrotactor user experience. Vibrotactor 1 may now be alow-impedance transmitter (TX). At least in some embodiments, themeasurements may occur relatively quickly as VT2 is disconnected fromthe high-voltage drive. When gathering data for machine learningestimation of hand pose, each RX VT may be measured relative to multipletransmitter vibrotactors. The receiver vibrotactors may experience someamount of distortion, when operating as a vibrotactor, if themeasurement window is overly long.

“Cmutual” in the example circuit diagram 750 of FIG. 7B may refer to themutual capacitance between VT1 and VT2. This may be the same as mutualcapacitance measurement 406 of FIG. 4. In some embodiments, Cmutual maybe between ½ pF and 5 pF. At least in some embodiments, the controller708 may have built-in hardware to measure mutual capacitance. Forexample, some controllers may implement a current digital-to-analogconverter (DAC) and timer to measure charge transferred to accumulatorcapacitors. The embodiments herein may be configured to make avoltage-based measurement to more easily observe the circuit on anoscilloscope.

In one embodiments, at the start of a measurement, the high-voltageswitch 73 and switch 7 are opened. These switches may remain openthroughout the measurement. The following steps may be repeated multipletimes (e.g., 10 times in some cases): 1) Close switches 2, 4, and 5.This may apply the same bias voltage on Cpositive and Cnegative so thedifferential measurement between them starts at zero. The bias voltagemay be ½ Vcc and may be a virtual ground. At least in some embodiments,the voltage used may vary since the ADC 755 may measure differentiallybetween Cpositive and Cnegative. 2) Close switch 1 and 3. The receiver(RX) may have parasitic capacitance to ground. Closing these switchesmay charge the parasitic capacitance to the voltage on Cpositive. 3)Open all switches, which may make RX high impedance. 4) Drive TX high.The coupling through Cmutual may increase the voltage at RX followingthe increase in TX. 5) Close switches 1 and 4. This may increase thevoltage on Cpositive, and the increase may be proportional to Cmutual.6) Close switches 1 and 6. This may charge the RX parasitic capacitanceto the voltage on Cnegative. 7) Open all switches. This may make RX highimpedance. 8) Drive TX low. The coupling through Cmutual may decreasethe voltage at RX following the decrease in TX. 9) Close switches 1 and5. This may decrease the voltage on Cnegative, and the decrease may beproportional to Cmutual. At the end of this sequence, the controller 708may measure the differential voltage between Cpositive and Cnegative.This measurement may be proportional to Cmutual. Accordingly, thisprocess may allow a vibrotactor (or other transducer) to act as a hapticfeedback provider and as a mutual-capacitance sensor.

Within this dual-purpose detector and haptic feedback providerfunctionality, substantially any type of transducer may be used. Forexample, voice coil transducers, linear resonant actuators (LRAs),electrically-activated jammers, fluidic actuators, or other types ofactuators may be used. In some cases, substantially any actuator havinga sufficient amount of conductor area may be configured to act like anelectrode and a transducer simultaneously (or at least within closesuccession). Accordingly, when any two transducers (e.g., vibrotactors)are brought together (as in FIG. 6B), they may become one through mutualcapacitance, and this mutual capacitance may be detected and used toprovide haptic feedback such as vibrations or buzzes. The controller maysend control signals to the transducer to provide the haptic feedbackand may immediately thereafter provide one or more charge detectionsignals to detect charge at the transducers (which in this case are alsoacting as electrodes). By implementing haptic feedback transducers aselectrodes, each haptic glove or other haptic device may not need toinclude both electrodes and separate transducers. As such, the hapticglove may be lighter and thus more comfortable to wear. Moreover,instead of having to run separate wires to both electrodes andtransducers, haptic devices using the embodiments herein may implement asingle wire to each combined transducer/electrode.

Thus, in this manner, any of the electrodes 701-706 shown in FIG. 7A mayalso function as transducers or actuators to provide haptic feedback tothe user. The controller 708 may measure mutual capacitance before,after, or while the controller 708 provides haptic feedback inputs tothe transducer/electrodes. The controller 708 may use the same wires toprovide the haptic feedback control signals as were used to detectmutual capacitance. Moreover, the controller 708 may receive feedbackfrom these electrodes before, after or while providing haptic feedbackinputs. The controller 708 may then use the received feedback tocalibrate other sensors communicatively coupled to the system.

For example, in some embodiments, one or more of the electrodes may be astretch sensor. The stretch sensor may be configured to detect an amountof stretch in the artificial reality device (e.g., haptic glove 710).The controller 708 may detect the amount of stretch while determiningthe mutual capacitance measurement between the at least two electrodes.The controller 708 may use feedback received from the other electrodes(e.g., 701-706) to calibrate the stretch sensor. The stretch sensor,which may be made of a stretchable material such as conductive silicone,having an insulating layer sandwiched between two layers of conductivesilicone, may generate a capacitance measurement as it is stretched out(e.g., on the back of a user's hand). This capacitance measurement maythen be refined by measurements taken at the electrodes 701-706.Alternatively, feedback from the stretch sensor may be used to calibrateany one or more of the electrodes 701-705.

In some embodiments, these stretch sensors may also be used aselectrodes. Indeed, as noted above, one or more stretch sensors may beplaced on the back of a haptic glove to identify where the user'sfingers bend. In other cases, the stretch sensors may stretch over thefingertips and onto the fingertips of the gloves, similar to theelectrodes 701-705 shown in FIG. 7A. In such cases, the stretch sensorsmay be used as electrodes capable of detecting touch at the user'sfingertips. Flexible piezo actuators may also be used as stretch sensorsand/or electrodes in a similar manner.

Turning now to FIG. 8, box 800A shows the front of a user's hand with ahaptic glove 810. Box 800B shows the back of a user's hand with the sameglove 810. As noted with other preceding figures, the embodiments hereinmay be implemented in a full glove (such as 810) or in a partial glove.The embodiments herein may also operate in footwear, bodywear, headwearor other haptic feedback systems. In glove 810 of FIG. 8, the thumb mayhave two RX electrodes (801 and 802). The index finger may have a TXfingertip electrode 803, as well as TX electrodes on the side of thefinger facing the thumb (804, 805, and 806). The two thumb electrodes801 and 802 may be configured to detect gestures. For instance, the twothumb electrodes 801 and 802 may be configured to detect a gesture ofsliding the thumb perpendicular to the index finger, (e.g., a push orpull). As a single TX electrode (803-806) slides from 801 to 802, thedetected charge on 801 may decrease as the detected charge on 802increases. Thus, the artificial reality device and/or acommunicatively-coupled controller may measure a granular position ofthe TX electrode as it slides across the thumb electrodes 801 and 802.Using this method, the user's fingers may act as a slider control as thefingers slide over the thumb electrodes.

Alternatively, the controller or artificial reality device may treateach charge measurement as a touch or no-touch measurement using apreestablished measurement threshold. In such cases, any chargemeasurement other than touching may be registered as a no-touch and onlya touch is indicated as a touch. Then, based on the timing of the touchor no-touch measurements from the thumb electrodes 801/802, thecontroller may determine which direction a user is sliding their thumbrelative to their finger (e.g., the pointer finger in the example shownin FIG. 8). In other examples, the electrodes may be placed on differentfingers, but may function in the same or similar manner. The electrodeson the side of the user's finger may also be used to detect the thumbsliding parallel to the index finger or sliding relative to otherfingers.

FIG. 9 illustrates an alternative glove embodiment in which an electrodeis mounted on the side of the glove's thumb. Box 900A of FIG. 9illustrates the palm side of a glove 910 that includes a cuff 903. Thecuff may be made from a loop of non-conductive stretchable material andmay be place over or attached to a finger (the middle finger in FIG. 9).The cuff may have an electrode 902 connected via a conductor to thecontroller 904, as shown in box 900B. This cuff may be repositionedanywhere along the finger, and the electrode 902 may be located at anyrotation relative to the glove. In some embodiments, the cuff 903 may besewn into the glove 910 once in position. The electrode 902 may be usedto detect contact between the thumb and the side of the middle finger.Thus, a user may implement the thumb electrode 901 and the cuffelectrode 902 to create a variety of gestures which may be used by theartificial reality device to control a user interface, to controlartificial reality objects, or to perform other actions. In some cases,for example, the thumb electrode 901 and the cuff electrode 902 may beused to form a finger gun in an augmented or virtual world, perhaps whenplaying a game or acting a role in a VR murder mystery, for instance.

FIG. 10 illustrates an alternative haptic glove embodiment in which aspecialized type of cuff is implemented. Box 1000A illustrates the palmside of a haptic glove 1010, and box 1000B illustrates the back side ofthe haptic glove 1010. As in FIG. 9, one electrode (1001) is mounted tothe thumb. The cuff 1003 may include a conductive material such as, forexample, conductive thread. The cuff 1003 may be located over anelectrode 1002 that may be integrated into the glove 1010. In somecases, the electrode 1002 may be located on the back of the hand (asshown in Box 1000B) to simplify conductor routing. The cuff 1003 may bea floating conductor, in which case the TX electrode 1002 maycapacitively couple to the cuff. The cuff 1003 may then capacitivelycouple to the RX electrode 1001. This embodiment may provide greatercontrol of the conductor routing (since the cuff 1003 is a floatingconductor) and thus may be allow more freedom in placing electrodesthroughout the glove 1010.

FIG. 11 illustrates an alternative embodiment of a haptic glove 1110 inwhich electrodes are positioned in a manner to detect additionalgestures. Box 1100A illustrates the palm side of haptic glove 1110, andbox 1100B illustrates the back side of the haptic glove 1110. Electrodes1101, and 1107 may be RX electrodes, and electrodes 1102, 1103, 1104,1105, and 1106 may be TX electrodes. When electrode 1101 toucheselectrode 1106, the controller 1108 may sense the gesture of the thumbtouching the palm near the base of the pinkie finger. When electrodes1102, 1103, 1104, and/or 1105 touch electrode 1107, the controller 1108may sense a closed hand. In some cases, electrode 1107 may be brokendown into multiple separate electrodes to detect which fingertip istouching the bottom of the palm. These additional gestures may providedifferent inputs for a more expressive user interface or may allow morenuanced interactions with virtual objects. In some embodiments,additional electrodes may be placed on facing sides of fingers tomeasure abduction, i.e., spread of fingers. Opposing electrodes may beRX and TX, respectively. In such cases, the distance between electrodesmay be determined by measuring capacitance between electrodes. Wiringmay be simplified if, for example, the ring finger electrodes in suchcases are both RX or are both TX electrodes on each side of the finger.In some cases, the electrodes may encircle the finger, as with the cuff1003 of FIG. 10.

FIGS. 12A and 12B illustrate an embodiment of a haptic glove 1210 thatincludes a plurality of different electrodes embedded in a variety ofdifferent locations on the glove. The controller 1201 may be connectedto each of these electrodes via conductors 1202. At least in someembodiments, any or all of these electrodes may function as transducersfor providing tactile feedback, as well as electrodes for measuringmutual capacitance. In some cases, the electrodes (e.g., 1203-1209 and1211-1214) may be embedded in an embroidered patch that is fastened tothe haptic glove 1210. For example, as shown in FIGS. 13A-13D, theelectrodes may be embedded in embroidered patches in a variety ofdifferent designs. Additionally or alternatively, the embroideredpatches 1301, 1302, 1303, and 1304 may themselves be electrodes,constructed out of conductive thread or other suitable material.

These embroidered electrodes may be very flexible and thus may becomfortable to wear. Electrode 1301 is illustrated in a serpentinepattern. In some embodiments, the path on the RX electrode may berotated 90 degrees from the path on the TX electrode to avoid variablecoupling that may be caused by varying alignment between the patterns.For example, the fingers may have the turn radiuses aligned in a linethat is perpendicular to the longitudinal axis of the finger. This mayallow for long runs that are flexible along the bend radius of thefinger. In some cases, the turn radiuses of the thumb may be alignedparallel to the longitudinal axis of the thumb. Technical embroiderymachines may be used to place the conductor (e.g., 1202 of FIG. 2) andmay also be used to stitch across the conductor. The pattern 1302 mayachieve higher conductor density by rotating the turn radiuses relativeto each other. The pattern 1302 may also be less sensitive to alignmentbetween the pattern on a TX and RX electrode.

It should be noted that, in these embodiments, the electrode conductordensity may not need to be 100% (e.g., a conductive foil). Less density,for example, may translate to more flexibility and more comfort. In somecases, 50% density may be used, and in some cases, density less than 10%may be used. For instance, the pattern 1303 exhibits a lower densitythan 1301, 1302 or 1304 and may thus provide greater flexibility. Inother cases, a conductive mesh (e.g., a conductive grid made ofconductive thread) may be used for an electrode. In at least some ofthese examples, the electrode and the conductor connecting the electrodeto the electronics may be a continuous wire. In some cases, a minimalistelectrode may be a single wire. In such cases, the designation betweenwhat is electrode and what is conductor may be whether the section canbe touched by another electrode of opposite function (RX vs. TX).Accordingly, as shown in FIGS. 12 and 13A-13B, the electrodes describedherein may be implemented in many different patterns and may be composedof many different types of materials that may conduct or not conduct.Some of these materials, such as conductive thread, may be advantageouswhen implementing into artificial reality devices as the devices may belighter and more flexible and thus more comfortable to wear over time.

FIGS. 14A and 14B illustrate an embodiment in which multiple electrodesmay be arranged in a pattern adjacent to each other to form a grid ofelectrodes. For example, in FIG. 14A, electrodes 1401, 1402 and 1403 maybe arranged in a circular pattern. As such, when an opposing electrode(e.g., 1405) comes into proximity with the grid of electrodes, acontroller that is communicatively coupled to the electrodes maydetermine a grid position indicating the location of the opposingelectrode 1405 relative to the grid of electrodes. Thus, for example, asshown in FIG. 14B, when the user slides the opposing electrode 1405 overelectrode 1401 and partially onto electrodes 1402 and 1403, electrode1401 may register a high capacitance reading as a majority of theopposing electrode 1405 is near or touching the electrode 1401.Electrodes 1402 and 1402 may each register a lesser amount of mutualcapacitance between themselves and the opposing electrode 1405. As theopposing electrode 1405 moves over the grid (which may include more orfewer electrodes than three), each individual electrode in the grid maycontinually report its current charge level. The controller may thencalculate, based on the input signals from each of the electrodes in thegrid, a combined grid position indicator indicating where the opposingelectrode is relative to the grid. In this manner, the user's thumb andpointer finger may function as a trackpad, where the trackpad iscompletely untethered and can move with the user as part of the glove orother haptic device.

In addition to or as an alternative to the embodiments described above,at least one embodiment may include the following: a glove having a palmside and a back side, and at least two electrodes positioned on at leasttwo separate fingertips of the glove. In this embodiment, the electrodesmay be formed from insulated wires located on the glove, and theinsulated wires may be routed from each of the at least two fingertips,respectively, to at least a portion of the back side of the glove. Forexample, as noted earlier with respect to FIG. 7, a glove 710 may beprovided that includes electrodes 701 and 702, positioned on the thumband pointer finger, respectively. Box 700A of FIG. 7 illustrates thepalm of the glove 710, and box 700B illustrates the back of the glove710.

In some embodiments, the controller 708 may be optional. Indeed, theglove 710 may be manufactured to include mesh or other materials formingthe glove, and one or more insulated wires (e.g., 707) that form theelectrodes. The insulated wires 707 may form any of the electrodes701-706 and may include other electrodes (not shown). In someembodiments, the glove 710 may be communicatively coupled to anartificial reality device. For example, the glove 710 may becommunicatively coupled to any of artificial reality devices 100, 200 or300 of FIG. 1, 2 or 3, respectively. This coupling may allow actuationsignals and/or measurement signals to be transmitted from the artificialreality device to the electrodes (e.g., 701 and 702) on the glove 710.

In some cases, at least one of the electrodes is positioned on an edgeof a finger on the glove 710. For example, electrode 701 may bepositioned on the edge of the thumb in the glove 710 shown in box 700A.Additionally or alternatively, electrodes may be positioned on the edgesof other fingers. These electrodes may be in addition to or analternative to the electrodes positioned on the fingertips (e.g.,702-705). For instance, in some cases, an electrode positioned on afingertip may be electrically connected to an electrode positioned onthe edge of the same finger. Each of these electrodes may be arranged indifferent forms.

Indeed, as shown in FIGS. 12A-12B and 13A-13B, the electrodes 1208-1214or 1301-1302 may be arranged in a spiral. The spiral may be a relativelydense spiral, with each loop of the wire wrapped closely to the otherloops, or the spiral may be relatively loose, with each loop of the wirewrapped relatively far apart from the other loops. In some cases, the“tightness” of the spiral or the amount of distance between loops may bereferred to as a fill density. If an electrode spiral (e.g., 1301) has afill density of 100%, then the loops of the spiral may be touching eachother, whereas if an electrode spiral has a fill density of 0%, then theloops of the spiral may be positioned as far apart as the length of wirewill allow. In some cases, the electrodes may be constructed with lessthan 50% fill density and, in some embodiments, the electrodes may beconstructed with less than 10% fill density.

FIG. 13C illustrates an embodiment in which an electrode 1303 is formedfrom a conductor arranged in a serpentine pattern with one or moreparallel runs. Thus, the electrode 1303 may begin with an initial lengthof wire, curve until perpendicular, then curve 180 degrees untilparallel for a length, then curve 180 degrees until parallel for alength, and so on. Such a serpentine pattern may also be manufactured ata given fill density including less than 50%, less than 10%, or at someother fill density. FIG. 13D illustrates an embodiment in which anelectrode is arranged in a distorted serpentine pattern. Such a patternmay mimic a human fingerprint. These serpentine electrodes may bepositioned around the radius of the fingertips of the glove (e.g., glove1210 of FIG. 12B). In some embodiments, serpentine electrodes (e.g.,1303) may be positioned on at least one finger of the glove, and spiralelectrodes (e.g., 1301) may be positioned on a thumb of the glove. Thismay help to avoid scenarios where parallel runs of wires may potentiallytouch each other.

In some cases, the insulated wires (e.g., 707 of FIG. 7) may be routedwith a specified minimum distance between them. In some embodiments,this specified minimum distance may be at least five millimeters. Insome cases, these wires may be used to form RX electrodes and TXelectrodes. Accordingly, in such cases, the wires forming the RXelectrodes and the wires forming the TX electrodes may be positioned atleast five millimeters apart to avoid interference. Gloves with RX andTX electrodes may be manufactured to include fewer RX electrodes than TXelectrodes. For example, in FIG. 7, electrodes 701 and 706 may be RXelectrodes and electrodes 702, 703, 704, and 705 may be TX electrodes.

The insulated wires that form these electrodes may be routed in a mannerthat avoids sharp bends in the glove 710. For example, as shown on theback side of glove 1210 of FIG. 12A, the wires 1202 may be routed awayfrom locations on the hand where sharp bends may occur such as on thepalm side of the fingers or hand. By routing the wires in a manner thatavoids the sharp bends, the wires may enjoy a longer lifespan beforebreaking due to being repeatedly bent. In some embodiments, electrodesmay be placed on different locations on the glove, other than thefingertips. For instance, electrodes may be positioned on the sides offingers such as electrodes 1204-1207 of FIG. 12A. In some cases, atleast two of these electrodes may be positioned along opposing sides ofadjacent fingers in the glove 1210. When placed along opposing sides ofadjacent fingers, the electrodes may be implemented to measure fingerabduction including rate of movement apart and together, as well asdistance between the fingers.

In some embodiments, the glove and corresponding electrodes may beconnected to a controller. For example, the wires 1202 of FIG. 12A maybe connected to controller 1201. This controller may, however, beoptional, and may not be included as part of the glove 1210. In caseswhere the controller 1201 is included with the glove, the controller maybe mounted to the back side of the glove 1210 or to some other part ofthe glove. In other cases, a controller may be implemented with thewires 1202 and glove 1210, but the controller may be remote to theglove, located in another location away from the glove. In such cases,the controller may be communicatively connected to the wires 1202 tosend and receive signals to and from the electrodes. In this manner,regardless of where the controller is located, the may communicate withand control the electrodes on the glove and, in some cases, may use theelectrodes to both measure mutual capacitance and provide tactilefeedback to the user.

Accordingly, the various embodiments described herein may provide avariety of different methods and systems for detecting touch in anartificial reality system. The embodiments may use a variety ofdifferent types of electrodes in multiple different configurations. Insome embodiments, the electrodes may function as both charge-detectingelectrodes and as actuators, providing haptic feedback upon receivingdriving signals. These electrodes may be employed on a variety ofdifferent haptic feedback devices including the many alternative typesof gloves described herein above.

As detailed above, the controllers, computing devices and systemsdescribed and/or illustrated herein broadly represent any type or formof computing device or system capable of executing computer-readableinstructions, such as those contained within the modules describedherein. In their most basic configuration, these computing device(s) mayeach include at least one memory device and at least one physicalprocessor.

In some examples, the term “memory device” generally refers to any typeor form of volatile or non-volatile storage device or medium capable ofstoring data and/or computer-readable instructions. In one example, amemory device may store, load, and/or maintain one or more of themodules described herein. Examples of memory devices include, withoutlimitation, Random Access Memory (RAM), Read Only Memory (ROM), flashmemory, Hard Disk Drives (HDDs), Solid-State Drives (SSDs), optical diskdrives, caches, variations or combinations of one or more of the same,or any other suitable storage memory.

In some examples, the term “physical processor” generally refers to anytype or form of hardware-implemented processing unit capable ofinterpreting and/or executing computer-readable instructions. In oneexample, a physical processor may access and/or modify one or moremodules stored in the above-described memory device. Examples ofphysical processors include, without limitation, microprocessors,microcontrollers, Central Processing Units (CPUs), Field-ProgrammableGate Arrays (FPGAs) that implement softcore processors,Application-Specific Integrated Circuits (ASICs), portions of one ormore of the same, variations or combinations of one or more of the same,or any other suitable physical processor.

Although illustrated as separate elements, the modules described and/orillustrated herein may represent portions of a single module orapplication. In addition, in certain embodiments one or more of thesemodules may represent one or more software applications or programsthat, when executed by a computing device, may cause the computingdevice to perform one or more tasks. For example, one or more of themodules described and/or illustrated herein may represent modules storedand configured to run on one or more of the computing devices or systemsdescribed and/or illustrated herein. One or more of these modules mayalso represent all or portions of one or more special-purpose computersconfigured to perform one or more tasks.

In addition, one or more of the modules described herein may transformdata, physical devices, and/or representations of physical devices fromone form to another. For example, one or more of the modules recitedherein may receive data to be transformed, transform the data into acharge measurement, output a result of the transformation to create aninput signal, use the result of the transformation to generate hapticfeedback, and store the result of the transformation as potentialfeedback for other sensors. Additionally or alternatively, one or moreof the modules recited herein may transform a processor, volatilememory, non-volatile memory, and/or any other portion of a physicalcomputing device from one form to another by executing on the computingdevice, storing data on the computing device, and/or otherwiseinteracting with the computing device.

In some embodiments, the term “computer-readable medium” generallyrefers to any form of device, carrier, or medium capable of storing orcarrying computer-readable instructions. Examples of computer-readablemedia include, without limitation, transmission-type media, such ascarrier waves, and non-transitory-type media, such as magnetic-storagemedia (e.g., hard disk drives, tape drives, and floppy disks),optical-storage media (e.g., Compact Disks (CDs), Digital Video Disks(DVDs), and BLU-RAY disks), electronic-storage media (e.g., solid-statedrives and flash media), and other distribution systems.

Embodiments of the instant disclosure may include or be implemented inconjunction with an artificial reality system. Artificial reality is aform of reality that has been adjusted in some manner beforepresentation to a user, which may include, e.g., a virtual reality (VR),an augmented reality (AR), a mixed reality (MR), a hybrid reality, orsome combination and/or derivatives thereof. Artificial reality contentmay include completely generated content or generated content combinedwith captured (e.g., real-world) content. The artificial reality contentmay include video, audio, haptic feedback, or some combination thereof,any of which may be presented in a single channel or in multiplechannels (such as stereo video that produces a three-dimensional effectto the viewer). Additionally, in some embodiments, artificial realitymay also be associated with applications, products, accessories,services, or some combination thereof, that are used to, e.g., createcontent in an artificial reality and/or are otherwise used in (e.g.,perform activities in) an artificial reality. The artificial realitysystem that provides the artificial reality content may be implementedon various platforms, including a head-mounted display (HMAD) connectedto a host computer system, a standalone HMD, a mobile device orcomputing system, or any other hardware platform capable of providingartificial reality content to one or more viewers.

The process parameters and sequence of the steps described and/orillustrated herein are given by way of example only and can be varied asdesired. For example, while the steps illustrated and/or describedherein may be shown or discussed in a particular order, these steps donot necessarily need to be performed in the order illustrated ordiscussed. The various exemplary methods described and/or illustratedherein may also omit one or more of the steps described or illustratedherein or include additional steps in addition to those disclosed.

The preceding description has been provided to enable others skilled inthe art to best utilize various aspects of the exemplary embodimentsdisclosed herein. This exemplary description is not intended to beexhaustive or to be limited to any precise form disclosed. Manymodifications and variations are possible without departing from thespirit and scope of the instant disclosure. The embodiments disclosedherein should be considered in all respects illustrative and notrestrictive. Reference should be made to the appended claims and theirequivalents in determining the scope of the instant disclosure.

Unless otherwise noted, the terms “connected to” and “coupled to” (andtheir derivatives), as used in the specification and claims, are to beconstrued as permitting both direct and indirect (i.e., via otherelements or components) connection. In addition, the terms “a” or “an,”as used in the specification and claims, are to be construed as meaning“at least one of.” Finally, for ease of use, the terms “including” and“having” (and their derivatives), as used in the specification andclaims, are interchangeable with and have the same meaning as the word“comprising.”

We claim:
 1. A system comprising: a glove having a palm side and a backside; and at least two electrodes positioned on at least two separatefingertips of the glove; wherein the at least two electrodes are formedfrom insulated wires located on the glove; wherein the insulated wiresare routed from each of the at least two fingertips, respectively, to atleast a portion of the back side of the glove; and wherein the at leasttwo electrodes positioned on the at least two separate fingertips of theglove form a single capacitor having a common dielectric between them,from which mutual capacitance between the at least two electrodes isdetectable.
 2. The system of claim 1, wherein the glove iscommunicatively coupled to an artificial reality device.
 3. The systemof claim 1, wherein at least one of the electrodes is positioned on anedge of a finger on the glove.
 4. The system of claim 1, wherein atleast one of the electrodes comprises less than 50% fill density.
 5. Thesystem of claim 1, wherein at least one of the electrodes comprises lessthan 10% fill density.
 6. The system of claim 1, wherein at least one ofthe electrodes is formed from a conductor arranged in a spiral.
 7. Thesystem of claim 1, wherein at least one of the electrodes is formed froma conductor arranged in a serpentine pattern with one or more parallelruns.
 8. The system of claim 1, wherein at least one of the electrodesis arranged in a distorted serpentine pattern.
 9. The system of claim 1,wherein one or more serpentine electrodes are positioned around theradius of at least one of the fingertips of the glove.
 10. The system ofclaim 1, wherein one or more serpentine electrodes are positioned on atleast one finger of the glove, and wherein at least one spiral electrodeis positioned on a thumb of the glove.
 11. The system of claim 1,wherein the insulated wires are routed with at least five millimeters ofspacing between each wire.
 12. An apparatus comprising: a glove having apalm side and a back side; and at least two electrodes positioned on atleast two separate fingertips of the glove; wherein the at least twoelectrodes are formed from insulated wires located on the glove; whereinthe insulated wires are routed from each of the at least two fingertips,respectively, to at least a portion of the back side of the glove; andwherein the at least two electrodes positioned on the at least twoseparate fingertips of the glove form a single capacitor having a commondielectric between them, from which mutual capacitance between the atleast two electrodes is detectable.
 13. The apparatus of claim 12,wherein wires forming RX electrodes and wires forming TX electrodes arepositioned at least a specified minimum distance apart on the glove. 14.The apparatus of claim 12, wherein the glove includes fewer RXelectrodes than TX electrodes.
 15. The apparatus of claim 12, whereinthe insulated wires are routed in a manner that avoids sharp bends inthe glove.
 16. The apparatus of claim 12, wherein the at least twoelectrodes are positioned along opposing sides of adjacent fingers inthe glove.
 17. The apparatus of claim 16, wherein the at least twoelectrodes positioned along opposing sides of adjacent fingers areimplemented to measure abduction.
 18. The apparatus of claim 12, furthercomprising a controller fastened to the back side of the glove.
 19. Theapparatus of claim 18, wherein the controller is configured to measuremutual capacitance between the at least two electrodes.
 20. Anartificial reality device comprising: a glove having a palm side and aback side; and at least two electrodes positioned on at least twoseparate fingertips of the glove; wherein the at least two electrodesare formed from insulated wires located on the glove; wherein theinsulated wires are routed from each of the at least two fingertips,respectively, to at least a portion of the back side of the glove; andwherein the at least two electrodes positioned on the at least twoseparate fingertips of the glove form a single capacitor having a commondielectric between them, from which mutual capacitance between the atleast two electrodes is detectable.